Method of making fireproof pulpboard.



llnrrnn fira'rns A'IEN'I OFFICE.

FRANK EUGENE KEYES, OF NEIV .YORK, N. Y., ASSIGNOR OF ONE-HALF TO ADDISON I3. POLAND, OF PATERSON, NEW JERSEY.

METHOD OF MAKING FIREPROOF PULPBOARD.

SPECIFICATION forming part of Letters Patent No. 645,035, dated March 6, 1900.

Application filed June 28, 1899, Serial No, 722,201. (No specimens.)

To all whom it nmy concern:

- Be it known that I, FRANK EUGENE KEYES, of New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Methods of Making Fireproof Pulpboard; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improved method of making fireproof pulpboard.

Heretofore pulpboard has been manufactured by first placing the woodin the grinder and in such manner that the stone will grind from the side thereof, the wood being pressed against said stone by a screw or hydraulic pressure, water being freely used to prevent the wood from burning. The fiber as ground from the wood is then passed through the sliver-catcher and thence through a screenin g-machine for the purpose of separating the coarse from the fine fiber, which latter is then ready for the wet-machine, the object of the latter being to gather the pulp from the liquid into sheet form.

In the manufacture of pulpboard and other fibrous articles the stronger the fiber the better the quality of board produced; but in the method above described the best and strongest part of the fiber is lost in the screeningmachine, thereby increasing the cost of manufacture and consequent production of an inferior product.

I'Ieretofore pulp has been made fireproof by first drying the pulp after it has passed through the wet-machine and prior to its being formed into sheets'or other articles. The pulp is then placed within a beating-engine containing fireproofing material and beaten to a pulp. In the method about to be described the expense attending the drying and beating of the pulp is avoided.

One object of the present invention is to economize in the material employed and reduce the expense incident to the process to a minimum.

A further object is to render the fiber fireproof during the initial operation of making the pulp.

WVith these objects in view my invention consists in certain novel steps in the method of making fireproof pulp, as hereinafter set forth, and pointed out in the claims.

In carrying out my method I grind the wood in theusual manner, and instead of employing water for preventing the wood or fiber being ground from burning by reason of its frictional contact with the stone or grinder a fireproofing solution is used, which latter not only keeps the wood and ground fiber in a thoroughlysaturated condition, but forms the vehicle used in the subsequent steps for forming the paper-board. After the ground fiber has been so thoroughly impregnated with the fireproofing solution as to render it absolutely fireproof it is passed through a slivercatcher for the purpose of separating the large sticks or slivers from the fiber, which latter is then ready for the wet-machine or presser,

as the case may require.

It will be apparent that the fireproofing material may be continuously kept at the desired strength by adding thereto from time to time a quantity of the stronger solution or ingre= dients from which the solution is made, thus avoiding the expense attending an entire -replenishing of the solution.

By the method described it will be seen that a superior grade of pulpboard may be quickly and cheaply made, and by the use of the tire proofing solution during the initial step in the method the process of drying and reheating the pulp is obviated, thus greatly reducing the cost of the finished article.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. Theherein-describedmethod, consisting in grinding wood in the presence of a fireproofing liquid. 7

2. The herein-described method consisting in grinding wood in the presence of a fireproofing liquid, separating the slivers from the pulp held in the fireproofing liquid and then forming the pulp into the desired shape.

' In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

FRANK EUGENE KEYES.

Witnesses:

H. D. JAMESON, A. NUrrINo. 

